"I'm at the right club, playing with the right players and I learn things all the time," he told MUTV.
"That's what is great about being at United. I improve all the time and I want to improve every season. I think I'm a better player now than five years ago.
"This season has been a great one for me. I've scored a lot of goals, the team have played very well and we're champions. It's amazing.
"It's a great feeling to win the league, I don't have the words to describe how it feels to be champions. I didn't think it would go to the final day of the season, but to be honest the feeling is even better.
"We've worked hard for nine months and I feel very proud to be champions."